A METHOD OF ACOUSTIC LANDMARK EXTRACTION FOR MOBILE ROBOT NAVIGATION

In this paper, we describe a method to extract multiple acoustic landm arks for the indoor navigation of a mobile robot. The environment is m odeled by specular vertical walls. An ultrasonic sensor mounted on the mobile robot seam around the surrounding walls and detects multiple e cho pulses. On the horizontal plane at the height of the ultrasonic se nsor from the floor, the two-dimensional environment is described by t he distance as a function of angle in the scan, Due to the specularity of the walls, the distance function has a manageable number of retror eflective parts that can be used as landmarks, By virtue of the consta ncy of the relative positions between the ultrasonic sensor and the Ha lls in scanning, the echo pulses reflected from a certain reflection p oints (RP) have the same time-of-Right in the ultrasonic scan data. We determine the position of an RP From the collection of the echo pulse s that hare the same time-of-flight. The direction to an RP is estimat ed from the orientation of the ultrasonic sensor at which the maximum magnitude is obtained For the group of echo pulses that correspond to the RP. The mean time-of-flight of the group of Echo pules provides th e distance to the RP. Some experimental results are provided to show t he validity and the performance of the proposed method.